1. Field of the Invention
This invention relates to powder dispensers of the squeeze-bottle-type. More specifically, this invention relates to a squeeze bottle powder dispenser with special means to help fluidize the powder and move it as a uniform air-powder suspension toward and out the discharge opening.
2. Description of the Prior Art
Squeeze-bottle powder dispensers have been used with foot and body powders, with insecticides, and a host of other products.
In the prior art, it has been customary to provide powder dispensers of the squeeze-bottle-type with simple nozzles in their upper end. Operation has been based on the general proposition that the pressure of air behind the powder will drive out an amount of powder for each squeeze of the bottle. Dispensers of this type, however, have delivered powder unevenly because of the inadequate powder fluidization. Clumps of powder have discharged: the nozzles have clogged. In short, the prior dispensers have not promoted the uniform suspension of powder particles desired by consumers of powder products.
There are in the prior art showings of powder dispensers in which a squeeze bulb has delivered air to the powder container at a point well down in the powder supply and a discharge tube has delivered powder from adjacent the air delivery point up to discharge. Examples are U.S. Pat. No. 2,202,079, issued May 28, 1940 to Ayres and U.S. Pat. No. 2,358,329, issued Sept. 19, 1944 to Houghton.
In neither of the above examples, however, has pressure been developed above the supply of powder not only to drive air down through a tube to a point near the lower end of a discharge tube, but also to in effect force air down through the powder to carry powder into the lower end of the discharge tube. Further, there has been no structure designed to direct the flow of air adjacent the lower end of the discharge tube and control the admixture of powder. Moreover, in the earlier examples there have been no employment of the increased height of the powder level due to the narrowing of the squeeze bottle in squeezing to facilitate introduction of powder into the discharge tube. The earlier examples have merely relied on the pressure-generating means, usually an independent squeeze bulb, to aspirate powder up the discharge tube to a discharge orifice.